MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { min(x, 0()) -> 0() , min(0(), y) -> 0() , min(s(x), s(y)) -> s(min(x, y)) , max(x, 0()) -> x , max(0(), y) -> y , max(s(x), s(y)) -> s(max(x, y)) , minus(x, 0()) -> x , minus(s(x), s(y)) -> s(minus(x, any(y))) , any(x) -> x , any(s(x)) -> s(s(any(x))) , gcd(s(x), s(y)) -> gcd(minus(max(x, y), min(x, y)), s(min(x, y))) } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..